Intra-abdominal injuries resulting from blunt torso trauma are a leading cause of morbidity in children and account for a significant number of ED admissions each year. Identifying these injuries early is critical to reducing morbidity and mortality from delayed or missed diagnoses. In recent years, CT has become standard for diagnosing many traumatic injuries, including those within the abdomen. At the same time, however, CT use in trauma and emergency care has expanded much faster than evidence for its use. “CT provides detailed and useful information about injuries and helps clinicians make informed management decisions,” explains James F. Holmes, MD, MPH, “but it also has its drawbacks. It exposes patients to relatively large radiation dosages, putting them at risk for radiation-induced malignancies.” Testing a Prediction Rule on Blunt Torso Trauma Recently, several smaller investigations have suggested that children with blunt torso trauma can be stratified by risk for intra-abdominal injury using a combination of readily accessible clinical factors. These studies, however, have been limited by their retrospective or single-center study designs and small samples. In an effort to overcome these limitations, Dr. Holmes and colleagues had a study published in Annals of Emergency Medicine that aimed to derive a prediction rule that identifies children with blunt torso trauma for whom CT would generally not be indicated. More than 12,000 children (average age, 11.1 years) from 20 EDs with blunt torso trauma were enrolled in the prospective analysis by Dr. Holmes’s study team. A prediction rule was created using a seven-item checklist that included patient history and physical examination variables readily available without the need for using laboratory or ultrasound...